1// Copyright 2022 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5#include "textflag.h"
6
7// func Syscall6(num, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2, errno uintptr)
8//
9// We need to convert to the syscall ABI.
10//
11// arg | ABIInternal | Syscall
12// ---------------------------
13// num | R4 | R11
14// a1 | R5 | R4
15// a2 | R6 | R5
16// a3 | R7 | R6
17// a4 | R8 | R7
18// a5 | R9 | R8
19// a6 | R10 | R9
20//
21// r1 | R4 | R4
22// r2 | R5 | R5
23// err | R6 | part of R4
24TEXT ·Syscall6<ABIInternal>(SB),NOSPLIT,$0-80
25 MOVV R4, R11 // syscall entry
26 MOVV R5, R4
27 MOVV R6, R5
28 MOVV R7, R6
29 MOVV R8, R7
30 MOVV R9, R8
31 MOVV R10, R9
32 SYSCALL
33 MOVV R0, R5 // r2 is not used. Always set to 0.
34 MOVW $-4096, R12
35 BGEU R12, R4, ok
36 SUBVU R4, R0, R6 // errno
37 MOVV $-1, R4 // r1
38 RET
39ok:
40 // r1 already in R4
41 MOVV R0, R6 // errno
42 RET
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